Portable internal combustion engine



March 18, 1941. D. R. CLARKE PORTABLE INTERNAL GOIBU$TION ENGINE Original Filed Aug. so, 193'! FIG.2.

INVENZOR DOUGLAS R CLARKE 7' QT ORNEY l1 il |l\l| 4 w its 0 o 5 4 8 2 a -91- M 2 6 4 5 x 7 L s f 4 HIV I 2 e w 2 H Z 6 n m I. 5 2 m a a 3 Patented Mar. 18, 1941 UNITED STATES 2.2mm I p PORTABLE INTERNAL OOQBUSTION ENGINE Douglas B. Clarke, Toronto, Ontario, Canada rlginal application August 30, 1931,

. Divided and I 21, 1938, 861131 N. 191,281

Serial No.

this application March 6 Claims- (01. 123-195) This invention relates generally to internal combustion engines of the type employed for marine purposes and is a division of my co-.- pending application Serial No. 161,652, filed August30, 1931.

More particularly, the invention concerns itself with marine engines of the portable outboard type wherein thefuel tank is in the form of a casting supported. between the cylinder of the internal combustion engine and the device for supplying fuel mixture to the cylinder. it is one of the principal objects of this invention to simplify engines of the above type by extending a passage from the cylinder through the fuel tank to the fuel mixture supplying device so that the fuel mixture is compelled to flow in heat conducting relation to the fuel in the tank before it is admitted to the cylinder of the engine. This construction not only avoids exterior plumbing, but also improves the operation of the engine in that it tends to maintain the fuel mixture at a. more uniform temperature. Another object of this invention consists in the provision of a' marine engine of the type set forth in the preceding paragraph wherein the fuel tank is in the form of a casting demountably secured to the top of the cylinder casting and wherein both castings have passages cast 30, integral therewith in a manner to register with one another in the assembled position of the parts to cooperate in forming the fuel mixture passage referred to above. I

' Aiurther object of this invention consists in casting a'lining in the fuel mixture passage so that the cross sectional area of thepassage is uniform throughout its length and the walls of the passage are relatively smooth.

In addition to the foregoing. the present ino vention contemplates supporting the ignition coil above-the fuel tank and extending the electrical .conductorsfrom the ignition coil to the igniter on the cylinfder through a conduit cast into the fuel "This feature also offers the possi- 5 bilityof eliminating exterior plumbing or wires and not, only simplifies the appearance of the engine... but insures protection for the electrical conductor-S.

The foregoing, as well as other objects, will 50 be made more apparent asthis description proceeds, especially when considered in connection with the accompanying drawing, wherein: I

Figure 1 is a sectional view through a portable marine engine embodying the present invention;

Figure 2 is a cross sectional view'taken substantially on=the plane indicated by the line 2-2 of Figure 1; and

Figure 8 is a cross sectional view taken substantially on the plane indicated by the line 3-8 of Fi ure 1. 5

For the purpose of illustrating the present invention, I have selected a portable marine engine of the single cylinder outboard type operating on the two cycle principle and having pro-v vision for removably clamping the same to a 10 boat to be propelled thereby. Upon reference to Figure 1, it will be noted that the engine proper comprises three castings, designated by the ref-- erence characters 15, I8, and 11. The intermediate casting l6 is detachably secured to the top casting I! by means of suitable studs 18 and is similarly secured to the bottom casting 11 by means of the'studs 19. The arrangement pro vides a unitary construction which is capable of being readily manufactured and assembled. The 20 casting I5 is in the form of a fuel supply tank 20 having a top wall 2| forming a support for the ignition coil 22 and for the carburetor 23. The intermediate casting i8 is fashioned to provide a cylinder 24 at the lower end thereof and 25 the bottom casting I1 is constructed to support a combined crankshaft and propeller shaft 25. The arrangement is such that the cylinder 24 of the engine is supported below the water level during operation of the engine in a manner that I 3 the same is effectively cooled by the transfer of heat from the cylinder to the surrounding water. As a consequence, the usual water jackets and circulating cooling system may be eliminated with the result that the weight of the engine, 85 as well as the cost .of manufacture, are substantially reduced.

The carburetor 23 is secured to the top wall 21 of the fuel tank castingv I5 and supplies fuel mixture to the intake port 26 in the cylinder through a passage 21 extending from the carburetor to the intake port 26 in the cylinder. In the present instance, a portion 28 of the passage 21 is cast integral with the fuel tank casting II and the remaining portion 29 of the passage is cast integral with the cylinder casting it in a manner to register with the portion 28 when the two castings are secured together by means of the fastener elements 18. A lining 30 is cast in the two portions of the passage 21 to provide the passage 21 with a uniform cross sectional area throughout its length and to also provide the passage with a smooth interior surface. As shown in Figure 1, the portion 28 of the fuel passage 21 is cast in one piece with the tributor Si and spark plug 32 by suitable electrical conductors 33. The distributor. as well as the spark plug 32, are located in the cylinder casting it and the spark plug is secured to one sidewall of the cylinder adjacent the upper end thereof to ignite thefuel mixture in the combustion chamber 34. The electrical conduc tors I3 extend upwardly from the distributor and spark plug through the cylinder casting It and fuel tank casting I! to the coil 22. The conductors are sealed from the fuel in the tank II by means of a conduit 38 which extends through the tank and is cast integral therewith. In this manner, the electrical conductors, as well as the spark plug and distributor, are completely concealed and protected from the weather. In this connection, it will also be noted that both the carburetor and ignition coil are enclosed by a cover 36 secured to the top wall II of the fuel tank casting II by fastener elements 31.

Upon reference to Figure 3, it will be noted that the side walls of the cover II are slotted adjacent the carburetor to provide ports 88 through which air is permitted to flow into the Venturi passage as of the carburetor. Fuel from the tank II is also supplied to the Venturi passage for mixture with the air through a jet 4! controlled by a needle valve 4i adiustably mounted to vary the area of the let from zero to a predetermined maximum. The fuel is supplied to the Jet from the tank through-the medium of a conduit 42 having one end extending into the fuel tank to a point adjacent the bottom of the latter and having the opposite end communieating with the valve controlled jet. The volume of fuel mixture supplied by the carburetor iscontrolled by a throttle valve '43 mounted for --sliding movement transversely of the venturi 8| opposite the fuel Jet 40 in a manner to vary the effective cross sectional area of the fuel mixture passage through the carburetor. The specific construction of the valve and the manner in which the same operates is defined'more in detail in my copending application Serial No. 268,977, filed April20, 1939, and also constituting a division of the parent application Serial No. 161,652, filed August 30, 1937. With the above construction, it will be noted that when the piston 48 in the cylinder 24 of the engine is on its suction stroke, fuel is drawn upwardly through 4 the conduit 42 and is elected into the. air stream sure resulting from burning of the fuel mixture in the combustion chamber 34 forces the piston downwardly on its power stroke and transmits a power impulse to the crankshaft 41 through the medium of the connecting rod 4|. Inasmuch as the propeller 49 is direotlyvsecured to the crankshaft, it follows that reciprocation of the piston effects the desired rotation of the pro peller. when the piston has completed its power stroke and is slain moved upwardly, the products of combustion are exhausted from the cylinder into the conduit II. The products of combustion are received by a muiiier Ii and are ex- 6 hausted from the muilier into a pipe." which extends below the level of the water so as to reduoe the decibels of noise of operation to the minimum. x

Thus, from the foregoing. it will be observed 10 that I have provided a marine engine of the outboard type composed of a relatively few simple parts capable of being inexpensively manufactured and assembled. It will also be noted that I have avoided exterior plumbing and exposed l5 ignition parts with the result that the engine not only presents'a neater appearance, but is also more reliable in operation.

What I claim as my invention is:

1. In a marine engine, the combination with a cast fuel 'tank and a cylinder located below the fuel tank having an intake port for fuel mixture, of a device supported on the top of the fuel tank and supplying fuel mixture to the intake port and communicating with the interior of the tank to receive fuel therefrom, means for supplying air to said device for mixture with the fuel, and means for conducting fuel mixture from the device to the cylinder intake port including a passage extending through the fuel tank and cast integral therewith.

2. In amarine engine, the combination with a cast fuel tank and a cylinder located below the fuel tank having, an intake port for fuel mixture, of a device supported above the fuel to tank for supplying fuel mixture to the intake port of the cylinder, means for supplying fuel from the tank and air to said device, means for conducting fuel mixture from the device to the intake port in the cylinder including a e 4 below the fuel tank operatively connected by means of electrical conductors extending through the conduit. 4. In a marine engine. the combination with a casting having a cylinder therein provided with" an intake port and a casting forming afuel tank located above the cylinder casting, of a device supported above the fuel tank 'forsup- 6o plying fuel mixture to the intake port'in the cylinder, meansfor supplying fuel from'the tank and air to the device. and means for conducting fuel mixture from the device to the intake port in the cylinder including a passage having a sec- 55 tion extending through the fuel tank in a manner to be surrounded by the fuel in the latter and cast integral with the fuel tank and also having a section cast integral with the cylinder casting in communication with the intake port in the cylinder and registeringwith the section aforesaid. p

'5. In a marine engine, the combination with a casting having a cylinder therein provided with an intake port and a casting forming a fuel tank located above the cylinder casting; of a device supported above the fuel tank for supplying fuel mixture to the intake port in the cylinder, means for supplying fuel from the tank and air to the device, means for conducting fuel mixture from the device to the intake port in the cylinder including a passage having a section extending through the fuel tank in a manner to be surrounded by the fuel in the latter and cast integral with the 'fuel tank and also having a section cast integral with the cylinder casting in communication with the intake port in the cylinder and registering with the section aforesaid, and a liner for the two sections of the passage having a uniform cross sectional area and a relatively smooth inner surface.

6. In a portable marine engine, the combination with a casting forming a fuel tank and a cylinder having an intake port, of means for supplying a fuel mixture to the intake port in the cylinder including a passage cast integral with the tank and extending through the latter in such a manner as to be surrounded by the fuel in the tank, and an ignition system for igniting the fuel mixture in the cylinder having electrical conductors extending through a. conduit passing through the tank and cast integral'therewith.

- DOUGLAS R. CLARKE. 

